Leaves From a Tree

import java.util.LinkedList;
import java.util.List;
import java.util.Scanner;

class Node<T> {
    T data;
    LinkedList<Node> childs;

    public Node(T data) {
        this.data = data;
        this.childs = new LinkedList<Node>();
    }

    public T getData(){
        return this.data;
    }
}

public class Tree<T> {
    Node root;

    public Tree(Node node) {
        root = node;
    }

    public Tree(T data) {
        root = new Node(data);
    }

    public boolean isEmpty() {
        return root == null;
    }

    public void add(T dataParent, T data) {
        Node node = getNode(root, dataParent);
        if (node != null)
            node.childs.add(new Node(data));
        else
            System.out.println("Node Parent tidak ditemukan");
    }

    public Node getNode(Node node, T data) {
        if (node.data == data) return node;

        for(Object currNode : node.childs) {
            Node returnNode = getNode((Node) currNode, data);
            if (returnNode != null) return returnNode;
        }
        return null;
    }

    public void printLeaves(Node current){
        //LENGKAPI
        if (!current.childs.isEmpty()) {
            current.childs.forEach((child) -> {
                printLeaves((Node) child);
            });
        } else {
            System.out.print(current.data + " ");
        }
    }

    public void access() {
        System.out.print(root.data);
        access(root, "  ");
    }

    private void access(Node node, String space) {
        System.out.println("");
        for(Object currNode : node.childs) {
            System.out.print(space + "->" + ((Node) currNode).getData());
            access((Node) currNode, space + "  ");
        }
        return;
    }

    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        int n = in.nextInt();
        int rt = in.nextInt();
        Tree pohon = new Tree(new Node(rt));
        for (int i = 0; i < n-1; i++) {
            int p = in.nextInt();
            int nd = in.nextInt();
            pohon.add(p, nd);
        }
        pohon.access();
        pohon.printLeaves(pohon.root);
        System.out.println("");
    }
}